Data from two longitudinal studies of older adults (a nationally representative sample of older adults, and the Alzheimer’s Disease Neuroimaging Initiative) has found that a brief cognitive test can distinguish memory decline associated with healthy aging from more serious memory disorders, years before obvious symptoms show up.
Moreover, the data challenge the idea that memory continues to decline through old age: after excluding the cognitively impaired, there was no evidence of further memory declines after the age of 69.
Analysis of 40 spinal marrow samples, 20 of which belonged to Alzheimer’s patients, has identified six proteins in spinal fluid that can be used as markers for Alzheimer's. The analysis focused on 35 proteins that are associated with the lysosomal network — involved in cleaning and recycling beta amyloid.
Data from 848 adults of all ages has found that brain volume in the default mode network declined in both healthy and pathological aging, but the greatest decline occurred in Alzheimer’s patients and in those who progressed from mild cognitive impairment to Alzheimer’s disease.
New research supports the classification system for preclinical Alzheimer’s proposed two years ago. The classification system divides preclinical Alzheimer's into three stages:
Stage 1: Levels of amyloid beta begin to decrease in the spinal fluid. This indicates that the substance is beginning to form plaques in the brain.
Stage 2: Levels of tau protein start to increase in the spinal fluid, indicating that brain cells are beginning to die. Amyloid beta levels are still abnormal and may continue to fall.
Initial findings from an analysis of cerebrospinal fluid taken between 1995 and 2005 from 265 middle-aged healthy volunteers, of whom 75% had a close family member with Alzheimer’s disease, has found that the ratios of phosphorylated tau and amyloid-beta could predict mild cognitive impairment more than five years before symptom onset — the more tau and less amyloid-beta, the more likely
Cognitive testing for dementia has a problem in that low scores on some tests may simply reflect a person's weakness in some cognitive areas, or the presence of a relatively benign form of mild cognitive impairment (one that is not going to progress to dementia). A 2008 study found that one of every six healthy adults scored poorly on two or more of 10 tests in a brief cognitive battery. Following this up, the same researchers now show that a more holistic view might separate those who are on the path to dementia from those who are not.
A French study has predicted with 90% accuracy which patients with mild cognitive impairment would receive a clinical diagnosis of Alzheimer's disease within the following two years. The best neurological predictors were cortical thickness in two brain regions (the right
A survey of 7,072 older adults in six provinces across China, with one rural and one urban community in each province, has identified 359 older adults with dementia and 328 with depression. There were only 26 participants who had doctor-diagnosed dementia reported and 26 who had doctor-diagnosed depression. Overall, 93% of dementia cases and 93% of depression were not detected.
Undetected dementia was strongly associated with low socioeconomic status such as a low educational and occupational class, and living in a rural area.
A survey of 7796 older adults (65+) living in three geographic areas in England has allowed us to compare dementia rates over time, with an identical survey having been taken between 1989 and 1994. The overall prevalence of dementia fell significantly, from 8.3% to 6.5%.
The finding provides further evidence that a cohort effect exists in dementia prevalence.
